实验3

实验1

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include<time.h>
 4 #include<windows.h>
 5 #define N 80
 6 
 7 void print_text(int line, int col, char text[]);
 8 void print_spaces(int n);
 9 void print_blank_lines(int n);
10 
11 int main()
12 {
13     int line, col, i;
14     char text[N] = "hi,November~"; 
15     
16     srand(time(0));//以当前系统时间作为随机种子
17     
18     for(i = 1;i<=10;++i){
19         line = rand() % 25;
20         col = rand() % 80;
21         print_text(line, col, text);
22         Sleep(1000);//暂停1000ms 
23     } 
24     return 0;
25 }
26 
27 //打印n个空格
28 void print_spaces(int n){
29     int i;
30     
31     for(i = 1;i<=n;++i)
32     printf(" ");
33 } 
34 
35 //打印n行空白行
36 void print_blank_lines(int n){
37     int i;
38     for(i = 1;i<=n;++i)
39     printf("\n");
40 } 
41 
42 //在第line行第col列打印一段文本
43 void print_text(int line, int col, char text[]){
44     print_blank_lines(line-1);    //打印line-1行空行 
45     print_spaces(col-1);          //打印col-1列空格 
46     printf("%s",text);            //在第line行col列输出text中字符串 
47 } 

实验2.1

 1 #include<stdio.h>
 2 long long fac(int n);
 3 
 4 int main()
 5 {
 6     int i, n;
 7     
 8     printf("Enter n:");
 9     scanf("%d",&n);
10     for(i = 1;i<=n;++i){
11         printf("%d!=%lld\n",i , fac(i));
12     }
13     return 0;
14 }
15 
16 long long fac(int n){
17     static long long p=1;
18     printf("p = %lld\n",p);
19     p=p*n;
20 
21     return p;
22 }

实验2.2

 1 #include<stdio.h>
 2 int func(int, int);
 3 
 4 int main(){
 5     int k = 4,m = 1,p1,p2;
 6     
 7     p1 = func(k,m);
 8     p2 = func(k,m);
 9     printf("%d,%d\n",p1 , p2);
10     
11     return 0;
12 }
13 
14 int func(int a,int b){
15     static int m =0, i= 2;
16     
17     i +=m +1;  
18     m = i + a + b;
19      
20     return m;
21 }

实验3

 1 #include<stdio.h>
 2 
 3 long long func(int n);
 4 
 5 int main()
 6 {
 7     int n;
 8     long long f;
 9     
10     while(scanf("%d",&n)!=EOF){
11         f= func(n);
12         printf("n = %d, f = %lld\n",n , f);
13     }
14     return 0;
15 }
16 
17 long long func(int n){
18     if(n==1)
19     return 1;
20     
21     return (func(n-1)+1)*2-1;
22 }